1. Field of the Invention
The present invention relates to a sawing machine and more particularly, to a table saw, which has a simple structure of scale system for easy reading.
2. Description of the Related Art
FIG. 1 is a top view of a table saw according to the prior art. According to this design, the table saw comprises a primary table 1, an auxiliary table 2, a saw blade 3, a fence 4, a scale system 5, and an index system 6. The auxiliary table 2 is movable relative to the primary table 1 by means of two parallel guiding bars 7. The fence 4 is movable on the primary table 1 and the auxiliary table 2 relative to the saw blade 3. The scale system 5 comprises a first scale 5a and a second scale 5b longitudinally provided at one guide bar 7 at different elevations. The index system 6 comprises a first index 6a provided at the fence 4, and a second index 6b provided at the primary table 1. When the auxiliary table 2 is set close to one side of the primary table 1, the user can know the distance between the fence 4 and the saw blade 3 by reading the reading on the first scale 5a indicated by the first index 6a. When the fence 4 is locked to the auxiliary table 2 and pulled outwards with the auxiliary table 2 relative to the primary table 1, the user can know the distance between the fence 4 and the saw blade 3 by reading the reading on the second scale 5b indicated by the second index 6b. 
The aforesaid scale system 5 and index system 6 enable the user to judge the distance between the fence 4 and the saw blade 3. However, because the first scale 5a and the second scale 5b are arranged adjacent to each other at different elevations, a reading error may occur, i.e., the user may read the reading on the wrong scale when measuring the distance between the fence 4 and the saw blade 3.
Therefore, it is desirable to provide a table saw that eliminates the aforesaid problem.